well technically, it is. survival of the fittest aka natural selection means the ability of living things to adjust and adapt to different situations. if you can't adjust, you die. it works in this situation where they created new rules to survive the apocalypse. You're probably confusing the meaning as "the strongest win" which is a wrong interpretation.
the whole thing you explained was literally just a longer version of my first comment. I have no idea what the point of all that was since u seem to agree with the gist of it lmfao. Reread my comment because your comprehension was so bad it's almost painful to see. There's only 1 part we seem to disagree on :
"it's about natural death due to biological constraints (getting too weak from sickness, not being able to be hungry for too long, etc)." Wrong. Google is one click away, check the full meaning of surivival of the fittest since you're limiting its definition for some reason. I won't bother explaining what you can just google.
Your last statement is just plain dumb. Knowing where medicine is is not "resilience" nor "adapting". If he did adapt in any way to his situation, he would've offered to go with the hounds outside to bring more medicine. He risked his life, and risked leaving his son fatherless, to steal from people who protected him instead of risking his life out there for it. But why you brought up this character an example when we were comparing the rule-system with an idiom I have no idea. This is irrelevant to what I was talking about anyway - one character's behavior is irrelevant to the definition of an idiom. If anything, you're just contradicting yourself by first saying "that's not survival of the fittest" and then beinging up how one of the characters "showcase survival of the fittest". Pick a lane. It's painfully obvious you're trying to argue just for the sake of it, so I'll leave it here.
